June 2016 - Boost - lists.preview.boost.org

A GUI Library
by jinhao 09 Nov '17

09 Nov '17

Hi, all I am developing a GUI library, it takes aim at easy-to-use and portable library for modern C++ methods. The project at http://stdex.sourceforge.net A git repository at http://nanapro.codeplex.com A brief at http://nanaproject.wordpress.com/2011/12/16/preliminary-study-of-nana-c-lib… Is there any interest in this library? Regards Jinhao

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Re: [boost] Boost CRC maintainer (Daryle Walker) missing in action?
by Olaf van der Spek 19 Jun '17

19 Jun '17

Hi Daryle, Any luck on your new setup? Gr, Olaf On Mon, Nov 28, 2011 at 1:11 AM, Daryle Walker <darylew(a)gmail.com> wrote: > I can look at it once I've finished my new setup. > > I had to reset my computer after a partial crash years ago. I never > got around to recreating my programming setup. My computer had been > at its maximum Operating System level back then, which is now 3 > versions behind. For the past few months, I've had my sister's old > laptop, with Windows Vista, and am trying to add a programming setup > to it now. > > > On Tue, Nov 22, 2011 at 7:18 AM, Beman Dawes <bdawes(a)acm.org> wrote: >> Hi Daryle, >> >> This guy has volunteered to take over maintenance of Boost CRC. Should >> we take him up on his offer? > >> ---------- Forwarded message ---------- >> From: >> Date: Wed, Nov 2, 2011 at 7:51 AM >> Subject: [boost] Boost CRC maintainer (Daryle Walker) missing in action? >> To: boost(a)lists.boost.org >> >> >> Hi, >> >> It looks like the Boost CRC maintainer (Daryle Walker) is missing in action? >> >> No response to tickets from the past 3 years. What's the procedure in this case? >> >> https://svn.boost.org/trac/boost/ticket/2492 >> https://svn.boost.org/trac/boost/query?component=crc&col=id&col=summary&col… > > -- > Daryle Walker > Mac, Internet, and Video Game Junkie > darylew AT gmail DOT com -- Olaf

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[msm] [statechart] unmerged PRs
by András Kucsma 23 May '17

23 May '17

Hi Everyone, There are a couple of PRs for msm and statechart by me and others, which didn't get any attention for many months now. Can the maintainers please take a look at them? https://github.com/boostorg/msm/pulls https://github.com/boostorg/statechart/pulls Thank you, Andras

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[clang] clang-cl expansion of macros
by Edward Diener 29 Apr '17

29 Apr '17

You can get clang-cl ( clang-win ) to show its VC++ emulated expansion of macros somewhat by passing the c++ option '-fmacro-backtrace-limit=0' to the compiler. It is still blessedly difficult to see the what and the why of clang's error messages when expanding macro using clang-cl, but at least it gives you a better chance of understanding where clang's emulation of VC++ has gone wrong. I have posted bug 27380 to the llvm/clang bug tracker at https://llvm.org/bugs/show_bug.cgi?id=27380 showing the main failure in VC++ emulation which I see when testing Boost PP with clang-cl.

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[container] moving a pre-built vector into a flat_set
by Sam Kellett 12 Mar '17

12 Mar '17

a common problem i encounter is that i have two stage's w/r/t to a large collection of data: building and querying. vector is obviously the king of building. flat_set is the king of querying. so what i often tend to do is build up a very large vector, sort it then create a flat_set using the flat_set(ordered_unique_t) constructor. however this still copies the entire vector into the flat_set, right? what i would like to be able to do is move the vector straight into the flat_set, something like: std::vector<T> data; flat_set data_set1(std::move(data)) // move vector in and sort it // or: std::sort(data.begin(), data.end()); // sort vector flat_set data_set2(ordered_unique_t, std::move(data)) // and move it in is this doable (am i just being blind?) or is there plans/interest for this?

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[nowide] Library Updates
by Artyom Beilis 04 Mar '17

04 Mar '17

Hello, Disclaimer: --------------- I recently discovered that virtually all e-mails sent from Yahoo account to any mailing lists go to user's spam due to recent Yahoo's DMARC policy. So I'm sending some important stuff from GMail account that almost certainly was missed: What is Boost.Nowide: -------------------------------- Boost.Nowide is a library that make cross platform Unicode aware programming easier. The library provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. It was inspiration and inspired by http://utf8everywhere.org/ development ideas and policy. Some updates regarding Boost.Nowide ------------------------------- 1. Library moved to github and its format is converted to modular boost layout: https://github.com/artyom-beilis/nowide 2. Fixed unsupported std::ios::ate flag by boost::nowide::fstream 3. Added some C++11 interfaces to boost::nowide::fstream 4. Added integration functionality with boost::filesystem: https://github.com/artyom-beilis/nowide/blob/master/include/boost/nowide/in… Note: that the links to the source code on review schedule aren't relevant, it should be: - Code: https://github.com/artyom-beilis/nowide - Documentation: http://cppcms.com/files/nowide/html/ Also the library is still looking for review manager. Artyom Beilis P.S.: I'm sorry if you are getting this as "duplicate"

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bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

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[MPL] A Proposal
by Bruno Dutra 16 Nov '16

16 Nov '16

Dear Community, About a year ago today, there was a proliferation of threads [1][2][3] in this mailing list concerning the future of Boost.MPL, or even whether it had a future at all, and opinions diverged widely on the matter. Many have expressed concerns about the fact Boost.MPL was long outdated and proposed major changes to open path for modernization, while some others argued against it, fearing unexpected and disastrous side-effects could propagate throughout the rest of Boost. A few questioned if it was worth it at all to spend any further resources on Boost.MPL given the fact new alternatives were coming up, such as Boost.Hana, which departed entirely from template metaprogramming, yet some argued TMP remained a competitive alternative for type computations in C++14 as it has been demonstrated by Peter Dimov in his impressive articles [4] on modern TMP. Amidst all this, a proposal by Robert Ramey [5] caught my attention and inspired me to develop what I call Metal [6], a template metaprogramming library designed on the same core principles as Boost.MPL, but written from the very beginning to take full advantage of C++11. Metal was not designed to be a strict drop in replacement for Boost.MPL though, it was rather meant to be regarded as a modern version of Boost.MPL's original API, diverging only where it could really benefit from modern C++ and that essentially means gains of several orders of magnitude in performance** and lower memory consumption. At this point Metal is very close to where I originally intended to bring it and I think it's time I gauge interest from the community on a modest proposal I've been maturing along the past year. As a modern approach to the same task that Boost.MPL was meant to address, I don't believe Boost would benefit at all from yet another TMP library that would essentially compete with Boost.MPL and even Boost.Hana in some cases, specially as maintainers of older code that depends on Boost.MPL would have to go through major refactoring efforts in order to benefit from such an addition to Boost. I would like to propose something different instead. My proposal is to make Metal officially into a new revision of Boost.MPL's API, essentially MPL2 as the original proposal by Robert Ramey put it, merging both into one single TMP library. The idea would be to provide a thin proxy for the current Boost.MPL API which would have two backends configurable by preprocessor switches: the original implementation and a another one based on Metal. This way older code using Boost.MPL could see immediate gains on performance by selecting the newer backend on supported compilers, while at the same time legacy code maintained on older compilers could still rely on Boost.MPL's impressive ability to run virtually anywhere. On the other hand, newer projects interested on pure type computations would have the newer API entirely available to them. This proposal also overcomes the problem of dealing with the maintainability of Boost.MPL, since it provides a way for smooth transition from legacy hacks required by ancient compilers into a cleaner and easier to maintain C++11 codebase, besides avoiding any breaking changes within existing code in the process. Furthermore, should this proposal make it into Boost, I would be naturally willing to take responsibility for the maintenance of Boost.MPL, which AFAIK has been maintained by the CMT for quite some time now, often with limited resources. Comparing Metal and Boost.MPL there are a few noteworthy differences. Metafunction Classes have proven themselves entirely unnecessary and have thus been removed altogether in favour of pure Lambdas (in the Boost.MPL sense). Moreover, iterators make little sense in a functional world, so these too have been removed despite the fact they may easily be emulated in the new design. Moreover Metal develops the concept of optionals, that is, its metafunctions only have a nested ::type defined when they may be successfully computed, what may be safely tested using metal::is_just and may also be used to SFINAE out of miscomputations. Finally I'd like to point out that Metal was designed to be portable across as many compilers as possible and three of the most popular ones are continuously tested using Travis and Appveyor: Clang 3.5+, GCC 4.8+ and MSVC 14 (2015). I hope this is a reasonable proposal and I look forward into your opinions about it. ** Even though I haven't published any benchmarks yet, an example follows just to back my claims regarding performance (just tested on my personal laptop running linux): //Generate a list containing 10 thousand instances of std::integral_constant, from 0 to 9999 using l = metal::enumerate_t<metal::integer<10000>>; // GCC 5.3 ~0.4 s // Clang 3.7 ~0.5 s //Transform a list containing 5 thousand numbers by squaring each element using l1 = metal::enumerate_t<metal::number<long long, 5000>>; using l2 = metal::transform_t<metal::pow<metal::_1, metal::integer<2>>, l1>; // GCC 5.3 ~5.6 s // Clang 3.7 ~3.0 s [1]: http://thread.gmane.org/gmane.comp.lib.boost.devel/257680 [2]: http://thread.gmane.org/gmane.comp.lib.boost.devel/257983 [3]: http://thread.gmane.org/gmane.comp.lib.boost.devel/258843 [4]: http://pdimov.com/cpp2/simple_cxx11_metaprogramming.html [5]: http://rrsd.com/blincubator.com/bi_suggestion/mpl-lite-or-mpl2/ [6]: http://brunocodutra.github.io/metal/ Regards, Bruno Dutra

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[graph] Sync develop with master?
by Murray Cumming 12 Aug '16

12 Aug '16

Now that Boost 1.61 is out, it would be great if the various fixes in boost graph's develop branch could be merged/cherry-picked/whatever to master, please. There seem to be a couple of years of fixes that have not appeared in a release. -- Murray Cumming murrayc(a)murrayc.com www.murrayc.com

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Review Schedule and Review Manager for PODs Flat Reflection (ex magic_get)
by Antony Polukhin 05 Aug '16

05 Aug '16

Hello, PODs Flat Reflection (or PFR) is a C++14 library that represents POD structures as tuples and provides tuple-like methods for PODs. Library has a set of predefined operators for PODs and useful functions for everyday use. Works with user-defined types without any macro or boilerplate code. Library: https://github.com/apolukhin/magic_get Docs: http://apolukhin.github.io/magic_get/ Boost Library Incubator: http://blincubator.com/bi_library/pfr-pod-flat-reflection/?gform_post_id=16… Could the PODs Flat Reflection library be put on review schedule? Anyone wishing to become a Review Manager for the library? -- Best regards, Antony Polukhin

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[config] RFC PR 82
by Domagoj Saric 01 Aug '16

01 Aug '16

Hi everyone, I am finally getting back to (trying to) contributing some of my personal projects to Boost. For two of those, Err (https://github.com/psiha/err) and especially Functonoid (a C++11 generalization and rewrite of my previous Boost.Function related work) I need some lower level codegen and/or optimiser control functionality (i.e. portable macros wrapping toolset specific attributes and pragmas) that I've added to my personal fork of Boost.Config and which I've now submitted in the subject PR (https://github.com/boostorg/config/pull/82) I don't expect this PR to be accepted as is/'just like that' so I'm opening this thread where we can discuss which of those changes/macros are welcome, which need more work and which, for some reason, should not be part of Boost.Config (and which, in turn then, I have to move to some 'internal implementation headers' in libraries that will need them). To avoid 'spamming' (and save time;) I'll skip the explanation of the individual macros as I expect them to mostly be self-explanatory (if not from their name then from the minimal Boost.Config documentation additions that are part of th PR). ps. I'll be on the (off) road for the next three weeks so I don't know when I'll be able to respond until I get back... -- "What Huxley teaches is that in the age of advanced technology, spiritual devastation is more likely to come from an enemy with a smiling face than from one whose countenance exudes suspicion and hate." Neil Postman

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[contract] Without the macros
by Lorenzo Caminiti 19 Jul '16

19 Jul '16

Hello all, In the last few years my professional and personal lives changed quite a bit limiting my ability to contribute to Boost. However, in my spare time I slowing continued to revise Boost.Contract hoping to be able to commit it to a Boost release someday (after the library was accepted 3+ years ago... https://groups.google.com/forum/?fromgroups=#!topic/boost-list/jQ7OjAmos_Y) While doing so I realized that leveraging C++11 lambda functions, Boost.Contract could be re-implemented without its crazy macros that alter C++ function declaration syntax. Boost.Contract still remains the only C++ library that implements *all* features of Contract Programming (a.k.a., Design by Contract or DbC): subcontracting, class invariants (also static and volatile), postconditions (with old and return values), preconditions, customizable actions on assertion failure (terminate, throw, etc.), optional assertion compilation, disable assertion checking while already checking other assertions (to avoid infinite recursion), etc. Furthermore, in its new incarnation Boost.Contract no longer uses crazy macros so it is easier to use, faster to compile, and gives readable compiler errors. For example: #include <boost/contract.hpp> int inc(int& x) { int result; boost::contract::old_ptr<int> old_x = BOOST_CONTRACT_OLDOF(x); boost::contract::guard c = boost::contract::function() .precondition([&] { BOOST_CONTRACT_ASSERT(x < std::numeric_limits<int>::max()); }) .postcondition([&] { BOOST_CONTRACT_ASSERT(x == *old_x + 1); BOOST_CONTRACT_ASSERT(result == *old_x); }) ; return result = x++; // Function body. } Or with subcontracting: #include <boost/contract.hpp> #include <vector> template<typename T> class pushable; // Arbitrary base to demo subcontracting. template<typename T> class vector #define BASES public pushable<T> : BASES { public: typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types; // Subcontracting. #undef BASES void invariant() const { // Checked in AND with base class invariants. BOOST_CONTRACT_ASSERT(size() <= capacity()); // Line 25. } virtual void push_back(T const& value, boost::contract::virtual_* v = 0) /* override */ { boost::contract::old_ptr<unsigned> old_size = BOOST_CONTRACT_OLDOF(v, size()); // Old values. boost::contract::guard c = boost::contract::public_function< override_push_back>(v, &vector::push_back, this, value) .precondition([&] { // Checked in OR with base preconditions. BOOST_CONTRACT_ASSERT(size() < max_size()); // Line 35. }) .postcondition([&] { // Checked in AND with base postconditions. BOOST_CONTRACT_ASSERT(size() == *old_size + 1); // Line 38. }) ; vect_.push_back(value); // Function body. } BOOST_CONTRACT_OVERRIDE(push_back) // For `override_push_back`. // Could program contracts for those as well. unsigned size() const { return vect_.size(); } unsigned max_size() const { return vect_.max_size(); } unsigned capacity() const { return vect_.capacity(); } private: std::vector<T> vect_; }; Full documentation and examples at: https://lcaminiti.github.io/boost-contract What do you think? Thanks, --Lorenzo P.S. The library can also be used without C++11 lambda functions (or any C++11 specific feature) but programmers have to write a fare amount of extra code to program the precondition and postcondition functors (using non-local functions, Boost.LocalFunction, Boost.Funsion, Boost.Lambda, or some other approach) so that might not useful in practice.

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[graph] Compilation error with adjacency_list and C++11
by Sebastien Loriot (GeometryFactory) 18 Jul '16

18 Jul '16

Hello, the program below does not compile at least with g++ 5.3.1 and clang++ 3.5.2-1 when using c++11 standard. If I comment line #1 it compiles. If I change #2 to undirectedS it compiles. Is there anything wrong in my code or is it a problem in boost's? Thanks, Sebastien. #include <boost/graph/adjacency_list.hpp> struct A { A(){} A(const A& ){} // #1 A& operator=(const A&){return *this;} }; typedef boost::adjacency_list<boost::listS, boost::vecS, boost::directedS, //#2 A > Graph; int main() { Graph g; boost::add_vertex(g); return 0; }

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smartptr maintained
by Karolin Varner 15 Jul '16

15 Jul '16

Hi, is smartptr still being maintained? There are four pull requests, one more than a year old. Best, Karolin Varner

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What kind of algorithms/data structures can enter in Boost
by Зайцев Александр 03 Jul '16

03 Jul '16

Hello. I am interested in developing data structures and some algorithms in Boost library. But one of the requierement for library is: "The library should be generally useful". What does it mean? I think, that i can add to the library some more data structures: suffix tree/array/automata, palindromic tree, modifications of stack/queue for getting min/max with O(1), Aho–Corasick(maybe it's algo already exist in Boost Library), maybe something else (kd-tree, for example). And algortihms: Manacker's algo for calculating palindromes number, Longest increasing subsequence, palindromic check. There are many algorithms, which i can implement to the Boost library. Also Boost.Math versus GNU MP library is very simple. In GNU MP there are many useful features. And i don't know? we need to provide these features to the Boost.Math or not. Ok, Who can explain me, what algorithms of those that i mentioned, is generally useful? What is useful for Boost, and what is useless? Thanks. -- Best regards, Zaitsev Alexander

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defect macro for thread_local?
by Oliver Kowalke 02 Jul '16

02 Jul '16

Hi, does boost provide a defect macro for thread_local (like BOOST_NO_CXX11_THREAD_LOCAL)? I couldn't find something similar int the boost macro reference. The macro would be helpful together with the feature-check to exclude compilers, that do not support the keyword thread_local (as gcc-4.7. and apple's compiler), from unit-tests. Oliver

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[1.61.0] building with Clang and c++11
by Richard Hadsell 02 Jul '16

02 Jul '16

I have downloaded 1.61.0 and want to build it with Clang. This is in my user-config: using clang : 3.5.0 : /netDISKS/master/netmt/LINUX_C65/app/clang/3.5.0/bin/clang++ : <compileflags>"-fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3 -Wno-overloaded-virtual -Wno-unused-function -Wno-unused-variable -Wno-c99-extensions -Wno-variadic-macros" <linkflags>"-fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3" ; When I build, I see warnings like these: ./boost/mpl/print.hpp:50:19: warning: in-class initialization of non-static data member is a C++11 extension [-Wc++11-extensions] const int m_x = 1 / (sizeof(T) - sizeof(T)); ^ ./boost/timer/timer.hpp:44:43: warning: 'long long' is a C++11 extension [-Wc++11-long-long] void clear() { wall = user = system = 0LL; } ^ ./boost/regex/v4/instances.hpp:124:34: warning: unknown warning group '-Wkeyword-macro', ignored [-Wunknown-pragmas] #pragma clang diagnostic ignored "-Wkeyword-macro" ^ When I add '-std=c++11' to the <compileflags> and <linkflags>, I get errors and warnings like these: clang-linux.compile.c.without-pth bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/link-static/threading-multi/alloc_lib.o error: invalid argument '-std=c++11' not allowed with 'C/ObjC' "/netDISKS/master/netmt/LINUX_C65/app/clang/3.5.0/bin/clang++" -c -x c -O3 -Wno-inline -Wall -std=c++11 -fPIC -gcc-toolchain /netDISKS/master/netmt/LINUX_C65/app/gcc/4.8.3 -Wno-overloaded-virtual -Wno-unused-function -Wno-unused-variable -Wno-c99-extensions -Wno-variadic-macros -march=core2 -pthread -m64 -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/container/build/clang-linux-3.5.0/release/instruction-set-core2/link-static/threading-multi/alloc_lib.o" "libs/container/src/alloc_lib.c" libs/locale/src/shared/localization_backend.cpp:54:22: warning: 'auto_ptr' is deprecated [-Wdeprecated-declarations] std::auto_ptr<localization_backend> res(new actual_backend(backends,default_backends_)); ^ ./boost/regex/v4/instances.hpp:124:34: warning: unknown warning group '-Wkeyword-macro', ignored [-Wunknown-pragmas] #pragma clang diagnostic ignored "-Wkeyword-macro" ^ What options do I need to add or remove to build and use boost with no errors and as few warnings as possible? -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

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New library? CallableTraits
by Barrett Adair 01 Jul '16

01 Jul '16

I posted about this a month ago, but I did not receive much response. Since then, I added an extended example use case, and I added a documentation section [1] that compares CallableTraits and Boost.FunctionTypes. I received some positive feedback this week in Aspen, and r/cpp also seemed to respond well [2], so I thought I'd give this another shot. Here are my questions for you: 1. Is there any interest in reviewing a future version of this for inclusion in Boost? 2. If so, does this belong in its own library, or should it be incorporated into Boost.TypeTraits or something similar? 3. What you like to see added, removed, renamed, or redesigned? I'd say CallableTraits is about 85% finished. Here's what's left: * Add INVOKE semantics to a couple of things for consistency (arity, etc) * Remove unused/undocumented code * Account for transaction_safe and C++17 noexcept * Finish/test the calling convention features * Finish/update the reference documentation * Write even more tests Cheers, Barrett [1] http://badair.github.io/callable_traits/doc/html/index.html#callable_traits… [2] https://www.reddit.com/r/cpp/comments/4ffmfs/callabletraits_never_write_ano… GitHub: https://github.com/badair/callable_traits Documentation from the top: http://badair.github.io/callable_traits/doc/html/index.html (reference section under construction)

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[build] Running 1 per N tests
by Adam Wulkiewicz 30 Jun '16

30 Jun '16

Hi, At Boost.Geometry we're using CircleCI for testing. They allow to run the tests concurently on N virtual machines. I'd like to alter my script to automatically redistribute the tests evenly across all of the machines, i.e. to run 1/N of the tests on each machine. The problem is that at Boost.Geometry we have a lot of nested project directories, i.e. b2 executed for some upper directory runs the tests in the test-suite in this directory and then follows nested projects defined by build-project directives, so runs the tests recursively. So e.g. if b2 was executed on some virtual machine for the most-top-level directory all of the tests would be built anyway. Do you have an idea how this could be solved without altering the tests structure? Is it currently somehow possible (though AFAIK it isn't) or would be possible to implement options allowing to e.g.: - run b2 only for a certain directory/Jamfile, e.g. --non-recursive - ignore arbitrary Jamfile directive, e.g. --ignore-build-project - run only 1 per N tests, an option used together with -jX but running tests only for one thread, e.g. b2 -i2 -j4 running only 1 per 4 commands starting from 2nd command ? The last option would be the most convenient for me. The tests would be divided as evenly as possible. It wouldn't require to use some workarounds i.e. traversing test directories recursively and running b2 manually for them which could result in low-quality redistribution, e.g. if some directory contained many tests and other small number of tests. Regards, Adam

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boost regression run.py fails with, fatal: Not a git repository
by Blower, Melanie 29 Jun '16

29 Jun '16

I'm trying to run.py on develop to report results with the Intel compiler. The script I use first downloads run.py. The git is failing partway through with this message Cloning into 'tools/quickbook'... Submodule path 'tools/quickbook': checked out 'c7cb99ac029593024f3f31a1ab2503820f1300d5' # Cleaning up "/localext3/mblower/sandbox/_try_dev/boost_root/bin" directory ... # Cleaning up "/localext3/mblower/sandbox/_try_dev/boost_root/bin.v2" directory ... # Cleaning up "/localext3/mblower/sandbox/_try_dev/results" directory ... # Getting sources (2016-06-29T12:24:07Z)... # Executing GIT command: /localext3/mblower/sandbox/_try_dev/boost_root> git submodule foreach "cd $toplevel && git submodule deinit $path" Entering 'libs/accumulators' fatal: Not a git repository (or any parent up to mount point /localext3) Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set). Stopping at 'libs/accumulators'; script returned non-zero status. # git_source_checkout failed with message "GIT command "git submodule foreach "cd $toplevel && git submodule deinit $path"" failed with code 256" I'm using a new server, the "master" results completed successfully last night. There's plenty of disk space. Any ideas?

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[boost-git] fiber not contained?
by Oliver Kowalke 29 Jun '16

29 Jun '16

Hi, I was asked several times why boost.fiber is not contained if boost's git-repo is cloned with git clone --recursive http://github.com/boostorg/boost.git. I'm wondering because boost.fiber is already included in the regression tests (master/develop). Oliver

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Attention library authors.. Library requirements testing is now active.
by Rene Rivera 29 Jun '16

29 Jun '16

As part of continued efforts to move testing to CI, to facilitate release management, and to provide more information to authors I've now implemented some testing changes: 1. Most libraries are now tested automatically if they have a usable test directory. There are still libraries that do not follow the requirements of having all their tests in just the single test directory. You can see which ones those are here < https://github.com/boostorg/boost/blob/develop/status/Jamfile.v2#L101>. Library authors should IMMEDIATELY make changes to their test/Jamfile's to follow the library requirements for testing. Before the next release I plan to blindly remove that custom list of extra test targets. 2. Most structure library requirements are now checked both in the regular full testing and in the CI testing. I've implemented a script to check for most of the library directory structure and integration requirements. The script runs as an additional CI job, currently in Travis. Here's one of those jobs < https://travis-ci.org/boostorg/boost/jobs/137506433>. At the moment it reports 17 libraries as having errors. There are also some warnings, i.e. not requirement violations but just some stuff that may be wrong. The script also runs as part of the general full testing and any problems are reported in each library's results as a single entry at the top of the tables. Here's how one of the test failures looks like < http://tinyurl.com/zbe9gal> [1] [2]. It would be great if library authors address those errors in some form ASAP. I know that for some of those reported libraries there will need to be some discussions as to how to best address the errors. Feel free to start additional threads for those as needed. [1] < http://www.boost.org/development/tests/develop/developer/output/teeks99-09f… > [2] Note there are currently some false failures in this aspect from a build system "bug". The bug is already fixed but tests will take some time to cycle to reflect the bug fix. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

11 23

Query: ADL vs MSVC2013 support
by Soul Studios 28 Jun '16

28 Jun '16

I have transplanted the advance/next/prev/distance member functions into ADL non-member functions in a current unreleased version of colony (plflib.org) My question is whether MSVC2013 support for these functions is more important to the boost community than them being ADL. There's a bug in MSVC2013 (fixed in MSVC2015, never backported to MSVC2013) that causes a compiler crash under certain template configurations - unfortunately the way that the ADL has to be implemented (I have tried several methods) causes this bug. The workaround would be to disable these functions in MSVC2013 only, as everything works fine in MSVC2010, MSVC2015, Clang 3.6-3.8 (have not tested earlier) and GCC 4.6-5.1 (have not tested earlier).

1 1

message: Build #2 is still failing.
by Robert Ramey 26 Jun '16

26 Jun '16

I'm getting these messages on aregular basis. They point to the url https://travis-ci.org/boostorg/serialization/builds/140270355 I can see the utility of this. It seems that this is due to some requirement that I'm not fulfillng in the serialization library test directory.... or something. What, if anything, should I do about this. Robert Ramey

2 1

enabling constexpr with Visual studio 2015 Update 3 (RC)
by Paul A. Bristow 24 Jun '16

24 Jun '16

I am trying to use the enhanced constexpr features and have (perhaps unwisely) downloaded the latest Visual Studio Update 3 (RC) to get as great a chance of achieving this as possible. https://blogs.msdn.microsoft.com/vcblog/2015/12/02/constexpr-in-vs2015-upda… (and later posts) I am unsure what I need to do to ensure that the compiler is enabled for use the latest features. I have added /std:c++14 to the options of the property for the project. (aside I also tried /std:C++latest but that works for some tasks but failed to compile with odd-looking errors in converter.hpp Error C2518 keyword 'typename' illegal in base class list; ignored \modular-boost\boost\numeric\conversion\detail\converter.hpp 453 // Trivial Converter : used when (cv-unqualified) T == (cv-unqualified) S // template<class Traits> struct trivial_converter_impl : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type ,BOOST_DEDUCED_TYPENAME Traits::result_type > ,public dummy_range_checker<Traits> {...} So I stopped trying that /std:c++latest option. What else should it do?) Running the modular-boost/libs/config/config_info.cpp program BOOST_NO_CXX14_CONSTEXPR [no value] BOOST_CONSTEXPR [no value] BOOST_CONSTEXPR_OR_CONST =const BOOST_STATIC_CONSTEXPR =static const These don't seem to be what I think that I would expect (constexpr and static constexpr). I want especially to use BOOST_STATIC_CONSTEXPR to get static constexpr. Do I need to also add #define BOOST_CXX14_CONSTEXPR in my program or elsewhere? (Doing this doesn't change BOOST_CONSTEXPR_OR_CONST from const to constexpr) Thanks for any suggestions. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

8 16

[typeof] Pull requests
by Adam Wulkiewicz 23 Jun '16

23 Jun '16

Hi, There are trivial pull requests in TypeOf waiting for merging (https://github.com/boostorg/typeof/pulls) One of them is more than 2 yo. Would it be possible to merge them? At least #3 or #4 should be merged. Regards, Adam

1 0

Additional Test Configurations
by Tom Kent 22 Jun '16

22 Jun '16

About a month ago I got three new machines dedicated to testing boost online (thanks to Boost Community/Steering Committee/Conservancy!). These three machines are currently running tests along with a couple other machines that I have. Now that things are up and running, I'm looking for some community input as to how best utilize them. Here's the current setup: teeks99-01 - Ubuntu 14.04 + Docker - gcc-4.4 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.5 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.6 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.7 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.8 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-4.9 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.0 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.1 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.2 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.3 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.4 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.6 (master + develop) Docker trusty - clang-3.7 (master + develop) Docker trusty + llvm.org/apt teeks99-02 - Ubuntu 16.04 + Docker - gcc-4.4 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.5 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.6 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.7 (master + develop) Docker precise + ubuntu-toolchain-r/test - gcc-4.8 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-4.9 (master + develop) Docker trusty + ubuntu-toolchain-r/test - gcc-5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.0 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.1 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.2 (master + develop) Docker trusty + h-rayflood/llvm - clang-3.3 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.4 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.5 (master + develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.6 (master + develop) Docker trusty - clang-3.7 (master + develop) Docker trusty + llvm.org/apt teeks99-03 - Ubuntu 16.04 + Docker - gcc-5 (develop) Docker trusty + ubuntu-toolchain-r/test - clang-3.7 (develop) Docker trusty + llvm.org/apt teeks99-05 - Ubuntu 14.04 (Azure VM) - gcc-4.8 (master) - clang-3.4 (master) teeks99-08 - Windows 2012 (KVM VM) - msvc-8.0 (master + develop) SP1 - msvc-9.0 (master + develop) SP1 - msvc-10.0 (master + develop) SP1 - msvc-11.0 (master + develop) Update 4 - msvc-12.0 (master + develop) Update 5 - msvc-14.0 (master + develop) Update 2 teeks99-09 - Windows 2012 (KVM VM) - msvc-8.0 (master + develop) SP1 - msvc-9.0 (master + develop) SP1 - msvc-10.0 (master + develop) SP1 - msvc-11.0 (master + develop) Update 4 - msvc-12.0 (master + develop) Update 5 - msvc-14.0 (master + develop) Update 2 I'm currently working on getting gcc-6 and clang 3.8, sorry they aren't in the list yet. I'm planning to retire the teeks99-01 shortly and converting the ancient teeks99-05 to something newer, still doing boost testing. All these configurations and the scripts that keep them cycling are on github at: https://github.com/teeks99/boost-build For each platform there are a couple configurations that I try to run frequently to give 'rapid' results as developers are committing code. The configurations for windows are set so that every few runs it will run the msvc-12.0 (develop) test, so that is never more than ~10hrs old. Similarly on linux, the gcc-5 and clang-3.7 (develp) tests get run every few hours. Just to give a feeling of the timing, Linux runs take .75-3 hrs and Windows runs take 1.5-4hrs, depending on compiler, os, hardware, etc. All these configurations have minimal compiler options set. MSVC + GCC builds have no options set, clang has `<cxxflags>-Wno-c99-extensions`. >From a lot of the discussing I've seen on the lists, it seems that there's a lot of work going into C++ 11/14/1z development. I was thinking it would be good to add some of those switches. Which ones? How many? Baseline Standard -std=c++98 (I believe this is the default for all the g++/clang++ instances above) -std=c++11/0x -std=c++14/1y -std=c++1z GNU Standard -std=gnu++98 -std=gnu++11/0x -std=gnu++14/1y -std=gnu++1z Clang Library -stdlib=libc++ -stdlib=libstdc++ Optimization -O2? Warnings -Wall -Wextra Others? I'm guessing that most of these will be of interest to at least a small subset of developers. There probably isn't a need to apply all possible combinations to all possible compilers however. (Not to mention that it would make the results matrix even more overwhelming.) Which combinations are important for you to see in the matrix? What do you think should be the 'rapid' configurations? I'm also thinking about additional compilers (in addition to gcc-6/clang-3.9 mentioned above), though these will take a bit of work on my part, so will only get implemented as I have time available. - gcc HEAD from GIT - clang HEAD from GIT - cygwin/gcc - mingw - clang on windows - Other? Thanks in advance for your input! Tom

6 12

[boost.process] 0.6 Alpha
by Klemens Morgenstern 21 Jun '16

21 Jun '16

Hi all, the boost.process 0.6 library is now in alpha, that is: it has some (compiling) examples, a documentation and tests that pass on windows as well as on linux. It basically allows you to manage a process like this: pstream pipe; child c("some_prog", "--some-arg", env["PATH"]+="C:/stuff", std_in < "data.csv", std_out > pipe, std_err > null, start_dir="./bin"); std::string data; pipe >> data; c.wait(); cout << c.exit_code() << endl; You can find the documentation here: http://klemens-morgenstern.github.io/process/ Get the source code from here: https://github.com/klemens-morgenstern/boost-process If you want to use it on windows, you currently would need to clone my boost.winapi fork also: https://github.com/klemens-morgenstern/winapi As for the scope of the library, it is meant to implement a small, portable layer to allow platform-independent process management. Thereby it's functionality is (unless I missed something) basically what is possible on posix as well as on windows. There are some platform extension, but I would not recommend to use them. It is also possible (though not yet documented) to write extensions, and if they work on both platforms I will gladly add them. It is however not the goal of the library, to be the be-all and end-all of process management; in past disscussions, different ideas where brought up, like implementing a DSEL for that or only allowing asynchronous communication. This library will never be that, since it would be much more fitting to build this on-top of it. E.g. a DSEL could be written (e.g. boost.shell) using boost.process underneath, so the library could concentrate only on the DSEL. It doesn't depend on boost.iostreams anymore, though it still uses boost.asio, boost.fusion and boost.filesystem. As for the open issues: some error handling is still lacking (but that'd be something like being unable to duplicate a handle), which would be required for proper extension, which is also why it's not documented. Also there's still an open discussion about the naming of the class and functions (child, system, spawn), so that may change also. But I consider this simple enough for a easy refactoring. If anyone has naming ideas, please tell me. One Idea was 'subprocess' but 'process::subprocess' just looks too strange to me. I hope you try it out, and give me some feedbacks. Or write angry error reports, both helps. Thanks! Klemens

8 32

Checking interest in stacktrace library
by Antony Polukhin 21 Jun '16

21 Jun '16

Hi, I've got some prototype for getting stack traces: https://github.com/apolukhin/stacktrace It's design is based on the idea that class for stacktrace must be fully noexcept, without dynamic allocations in constructors and as simple as possible. Is there interest in it? What functionality would you like to have in it? -- Best regards, Antony Polukhin

9 10

Re: [boost] proposed new library "histogram"
by Bjorn Reese 20 Jun '16

20 Jun '16

On 05/05/2016 12:21 AM, Hans Dembinski wrote: > https://github.com/HDembinski/histogram I suggest that you use non-intrusive serialization and place that in separate headers, so there is no dependency on Boost.Serialization unless you need it.

2 4

Checking interest in clang-{format, tidy} configurations
by jerry.c.t＠web.de 19 Jun '16

19 Jun '16

Hi, is there an interest for common boost clang-format and clang-tidy (only the module readability-identifier-naming) configurations to inforce consistent layout and naming style? For clang-format there are predefined styles like llvm, google etc. I think about adding a new predefined style 'boost' to clang-format. But first i would start with a separate _clang-format file. For clang-tidy there are no predefined styles thus i would simply create a _clang-tidy file. Best regards, Jerry

2 1

Feature request: variant::view
by TONGARI J 19 Jun '16

19 Jun '16

Hi, Sometimes we need to view a value as a variant and we don't want to copy the value into a variant. It'd be great if there's a variant::view that works like a variant but holds a reference to the value instead. The constructor should allow any reference to the types as in the variant, and a constructor that takes a reference to the variant, e.g. template<class T1, class T2...> class variant<T1, T2...>::view { view(T1&); view(T2&); ... view(variant&); }; And we can use apply_visitor/get on a view as on a variant. Thoughts? Thanks.

2 2

Boost's List of improvements
by Зайцев Александр 19 Jun '16

19 Jun '16

Hello. I will prepared Boost's list of improvements. I can realize it. Maybe, some algorithms I only can't find in Boost. And i think, that if i will implement algorithms from this list, it's will be great. Improvement list for Boost.Algorithm Boost.Algorithm(String) 1) Manacker's Algorithm: finding all palindromes in string O(N). 2) Different algortihms based on suffix arrays and suffix trees: Boost.Algorithm(Numbers) 1) Checking for number's simplicity by BPSW test. O(logN). 2) Effective factorization algorithms: Po, Po-1, Bents algo, Po-Monte-Carlo, Ferms algo. 3) Longest increasing subsequence Boost. Container 1) Modifications of queue and stack for searching min/max element with O(1). Maybe, I forgot something. -- Best regards, Zaitsev Alexander

1 0

Book
by Robert Ramey 18 Jun '16

18 Jun '16

I've attached an epub version of my "book". You should be able to just click on it and have the apple book reader popup and then be able to read it. The apple book reader has some interesting features. a) the book looks pretty good considering I didn't have to put to much effort into the formatting etc. b) For our purposes the best part is that you can easily annotate the book! There are three icons in the upper left corner. One to display the table of contents and other one for "notes" You can highlight text and add a note to it then save the book !. This is perfect as far as I'm concerned. Please don't spend time "copy editing" it. The whole thing needs to be gone over with a fine tooth comb with the idea of making the text more readable and clear, that the examples are in sync with the text, probably more narrative etc. etc. I'm really mostly concerned that the concepts are readable and explained to the target reader. Since I discovered the notion of semiring I understand the my C++ type algebra fulfills all the requirements of a semiring. And there is a large list of theorms which apply to semirings. I don't intend to add too much to the section, at least for now. It is very interesting but but right not it doesn't yet have a practical application. I'm hoping that will change but for now I it's as far as I want to go with this. This section will also need some work as far at the math is concerned. There are some issues with the notion of an inverse of a type etc which are still not really finished. But for now I think I've got the concepts outlined. It generates a book 60 pages long.

4 4

Re: [boost] [Boost-users] Checking interest in stacktrace library
by Antony Polukhin 18 Jun '16

18 Jun '16

2016-06-18 17:49 GMT+03:00 Edward Diener <eldiener(a)tropicsoft.com>: > On 6/18/2016 6:34 AM, Antony Polukhin wrote: > >> Is there interest in it? >> What functionality would you like to have in it? >> > > Documentation is always helpful. > Yeep, that's currently missing :( If in short: namespace boost { namespace stacktrace { class stacktrace { public: BOOST_STATIC_CONSTEXPR std::size_t max_symbol_width = 256; typedef boost::array<char, max_symbol_width> frame_t; stacktrace() BOOST_NOEXCEPT; stacktrace(const stacktrace& bt) BOOST_NOEXCEPT; stacktrace& operator=(const stacktrace& bt) BOOST_NOEXCEPT; ~stacktrace() BOOST_NOEXCEPT; std::size_t size() const BOOST_NOEXCEPT; frame_t operator[](std::size_t frame) const BOOST_NOEXCEPT; }; template <class CharT, class TraitsT> std::basic_ostream<CharT, TraitsT>& operator<<(std::basic_ostream<CharT, TraitsT>& os, const stacktrace& bt); }} So you can construct stacktraces, copy them and output them to streams: std::cerr << stacktrace(); -- Best regards, Antony Polukhin

1 0

Library addition request
by Gerrit Daniels 18 Jun '16

18 Jun '16

Hello, I've written a library that implements automatic serialization of user defined types. You can find it here: https://github.com/gerritdaniels/ctrl. I was wondering if this is something that could be added to the boost library. Kind regards, Gerrit Daniels.

6 10

Stand-alone Boost.Python
by Stefan Seefeld 18 Jun '16

18 Jun '16

Hello, I have started working on a new SCons-based build infrastructure for Boost.Python that allows the Boost.Python code to be compiled stand-alone against a pre-installed Boost. I have checked in a first version to the develop branch, and have enabled Travis-CI to use that. While this works reasonably well, and provides a much simpler workflow for developers wanting to contribute to Boost.Python, it isn't (yet) entirely feature-complete. Notably, running this on Windows (using MSVC) produces errors. I'd appreciate any help with this, especially from Windows users who are more familiar with MSVC than I am (that shouldn't be hard, given I have next to no experience with using MSVC :-) ). Building Boost.Python is now very simple: * clone the repo via `git clone https://github.com/boostorg/python.git` and switch to the 'develop' branch * configure a build via `scons config --python=... --boost-prefix=...` * build and test via `scons test` Hopefully this will make it much simpler to contribute and test patches, so we can work down the list of accumulated PRs and issues. (For avoidance of doubt: for the immediate future I have no intentions to replacing the official bjam-based build system. But once the new one has proven to be stable enough, I expect to actually build stand-alone releases for Boost.Python.) Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

1 0

Using Boost with VS 14.0 update 3 RC and Clang 3.8.0 (from CodeBlocks IDE) compile fails in MS type_traits is_assignable
by Paul A. Bristow 15 Jun '16

15 Jun '16

I am trying to check a program that compiles on VS with 14.0 update 3 RC and on Codeblocks IDE GCC 5.3 compile OK, but CodeBlocks Clang 3.8.0 fails: C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits:524:45: error: '_To' does not refer to a value : integral_constant<bool, __is_assignable(_To, _From)> I:\modular-boost\boost\mpl\aux_\preprocessed\plain\or.hpp|58|error: pasting formed 'BOOST_PP_TUPLE_ELEM_O_3(', an invalid preprocessing token [-Winvalid-token-paste] and terminally many more. clang++.exe -Wall -std=c++14 -m64 -fexceptions -O4 -m64 -std=c++14 -fms-extensions -Wall -m64 -fms-compatibility-version=19.00 -II:\modular-boost -c J:\Cpp\hellos\fixed_point_constexpr\fixed_point_constexpr.cpp -o obj\Release\fixed_point_constexpr.o I see some discussion of similar problem on https://groups.google.com/forum/#!topic/boost-list/MvqaK4SDy_c and a possible apparent fix on https://github.com/boostorg/type_traits/pull/24 Any suggestions for working around this problem? Paul PS I may try to use a *nix platform for this. --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

2 1

[density] new library
by Giuseppe Campana 14 Jun '16

14 Jun '16

Hi to all, I'm working to density, a C++11 header-only library for heterogeneous containers and lifo memory management. It is not complete, but it is very close (and usable already). Just to avoid confusion, the test project of density contains a sub-module called testity, that in a near future will become a separate library. I'm wondering if it may become a valid proposal for a new library. In any case, any kind of feedback is welcome. Source code at https://github.com/giucamp/density Documentation at http://peggysansonetti.it/tech/density/html/index.html Regards, Giuseppe Campana.

6 9

[property_tree] Quoting documentation
by alainm 13 Jun '16

13 Jun '16

Hi, I am using property_tree for a project, and I'd like to provide a description of the format. That text is exactly what I need: http://www.boost.org/doc/libs/1_61_0/doc/html/property_tree/parsers.html#pr… I am going to provide a link to the doc, but would need to insert the text into the documentation pdf too (some people actually still read paper). Is it possible and what kind of copyright text should I use ? Thanks Alain

2 1

Start to contribute to Boost.
by Зайцев Александр 11 Jun '16

11 Jun '16

Hello. I very want to start contribute to Boost library. I want to help this project. And... maybe for start i can try to fix some bugs. Can you give me some pieces of advice, what i can do at start? Thanks. -- С уважением, Зайцев Александр.

3 2

Pimpl Again?
by Vladimir Batov 10 Jun '16

10 Jun '16

Don't laugh but it is only fairly recently at work that I managed to move all our supported platforms to C++11. So, then, I started moving our code to C++11 (what a delight!) and stumbled upon my old pimpl which is used quite a bit around my workplace for all its good properties... :-) Now C++11-ed piml turned out to be very small and very basic. So basic it felt it did not have the right to exist. Still, it encapsulates and enforces the "proper" pimpl properties and behavior, reduces implementation minutia and offers a recognizable deployment pattern (helps other people reading the code). Over the years IMO the technique has been proven as legitimate and useful, a basic but important building block... rather than a curiosity item. Unfortunately, despite many articles and a few Sutter's GotWs about it there is nothing ready-to-go like std::unique_ptr. I feel that pimpl and its deployment pattern need to be codified, described, "standardized" and in our toolboxes to stop/avoid everyone re-inventing the pimpl and making the same mistakes. IMO Boost is best positioned for that. Do you think we might review what I've got and/or maybe collectively come up with something better... It's no MPL or Hana but as std::unique_ptr it's one of the first "little things" I personally reach out for in my everyday work. IMO having pimpl in Boost would save quite a few hours of frustration for many. Thoughts? No pressure. I am easy either way. :-) https://github.com/yet-another-user/pimpl Docs are freshened up but still somewhat out of date. Apologies.

15 84

[config] Changes needed for VC++ 2015 Update 3?
by Beman Dawes 09 Jun '16

09 Jun '16

The VS 2015 Update 3 release candidate has been announced. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/compiler-improvements-in… (The following is partially for Boost developers who care about msvc, and partially to remind myself of what may need to be done to support update 3. It will be several weeks before I can work on this, so if any of the other config maintainers want to step in, please do so.) Update 3 supports standards versioning switches similarly to gcc, clang, and other compilers. We probably want to update Boost.Config accordingly. See https://blogs.msdn.microsoft.com/vcblog/2016/06/07/standards-version-switch… Update 3 fixes lots of constexpr bugs, so we need to review whether or not BOOST_NO_CXX11_CONSTEXPR is still required. Note that in develop there is an undocumented config macro BOOST_MSVC_CXX11_CONSTEXPR that turns off BOOST_NO_CXX11_CONSTEXPR to facilitate testing. Update 3 fixes the expression SFINAE issues that were causing most of the Boost develop test failures. https://blogs.msdn.microsoft.com/vcblog/2016/06/07/expression-sfinae-improv… Quoting from that: There are still three failing tests in the Boost [develop] test suite when compiling with MSVC. Two test failures relate to using the noexcept operator in a template type argument. We currently parse it immediately, even in a dependent context. One test failure is a Boost library issue that we’ve reported to the [library's] maintainers. There are still known update 3 expression SFINAE issues (see "What remains to be done?" in the blog article) so do we continue to define BOOST_NO_SFINAE_EXPR? There is an undocumented BOOST_MSVC_SFINAE_EXPR macro in develop that turns off BOOST_NO_SFINAE_EXPR, so it is easy for developers to use msvc expression SFINAE if the want to. But our usual criteria for a _NO_ macro is not full compliance, but whether or not Boost code works with a feature. So using that criteria for update 3 we would remove BOOST_NO_SFINAE_EXPR. Opinions? --Beman <aside> We always urged Microsoft to test their releases against Boost. For update 3 expression SFINAE, they did exactly that. Thanks to Microsoft's Andrew Pardoe for coordinated the effort and to Xiang Fan for running the tests and tracking down the reason for each test failure. An undocumented Boost.Config macro BOOST_MSVC_SFINAE_EXPR to support their testing. The approach was to run tests for all libraries with the normal test setup, and then run again with BOOST_MSVC_SFINAE_EXPR defined. If the problem was with the Boost library, Xiang then reported it to me. I need to review a long series of email exchanges with him to make sure I alerted library maintainers to any Boost problems. </aside>

5 9

Boost Best Practice text download option fails.
by Fletcher, John P 08 Jun '16

08 Jun '16

This is a very interesting item to me. https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook This has an option at the end to download as plain text. This fails on my browser (Firefox) with "Corrupted Content Error" which I have never seen before. Please sort this out someone. John

2 1

[variant] spirit broken
by Jürgen Hunold 08 Jun '16

08 Jun '16

Hi Antony, according to git bisect, your commit ----------- commit b3650685f941a0c35cadfd878a185f274e132788 Author: Antony Polukhin <antoshkka(a)gmail.com> Date: Sat May 28 01:29:52 2016 +0300 Variant constructors and assignment operators now do not participate in overload resolutions if variant can not hold the input type (trac 5871, trac 11602) ------------ broke Boost.Spirit. The test failures can be seen in the regression matrix. For example: http://www.boost.org/development/tests/develop/developer/output/Flast-FreeB… fails with ../boost/variant/variant.hpp:1152:7: note: while substituting deduced template arguments into function template 'operator=' [with T = boost::variant<boost::spirit::info::nil_, std::__1::basic_string<char>, boost::recursive_wrapper<boost::spirit::info>, boost::recursive_wrapper<std::__1::pair<boost::spirit::info, boost::spirit::info> >, boost::recursive_wrapper<std::__1::list<boost::spirit::info, std::__1::allocator<boost::spirit::info> > > >] class variant ^ ../boost/spirit/home/support/info.hpp:29:12: note: definition of 'boost::spirit::info' is not complete until the closing '}' struct info It seems that the commit somehow disabled support for recursive variant usage. To reproduce this, just run the Spirit regression test. Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

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[Spirit] real_policies<> and 1.0#NAN
by Pete Bartlett 08 Jun '16

08 Jun '16

Hi, Boost.Spirit is not sure of itself when it comes to parsing representations of infs and nans such as “1.0#NAN”. The docs [1] for the default real_policies<T> for parsing numbers say: “[…] with the additional detection of NaN and Inf as mandated by the C99 Standard and proposed for inclusion into the C++0x Standard: nan, nan(...), inf and infinity (the matching is case-insensitive). This corresponds to the following grammar:” The first sentence suggests that 1.0#NAN etc will not be parsed. But the grammar itself then says: <quote> nan = -lit("1.0#") >> no_case["nan"] >> -('(' >> *(char_ - ')') >> ')') ; inf = no_case[lit("inf") >> -lit("inity")] ; </quote> suggesting that "#1.0NAN" is intended to parsed, but "#1.0INF" is not! Then the in-code docs [2] however suggest that both "1.0#NAN" and "1.0#INF" are intended to be parsed: <quote> // The second call allows to recognize representation formats starting // with a 1.0 (such as 1.0#NAN or 1.0#INF etc.). </quote> However, the actual code fails to parse either of these these. This is because in [3] the presence of the "0" causes frac_digits to be non-zero and so the "traits::is_equal_to_one(..)" condition is never tested. In the case "1.#NAN" (without a zero) frac_digits is zero so the condition is tested and we enter the traits::parse_nan code, but now the text parsed to this sub-parser is "#NAN" and the parser does not cater for the initial "#". Could the maintainers state which behaviour is intended...hopefully I may be able to supply a patch to docs/code/tests knowing that. Regards, Pete [1] http://www.boost.org/doc/libs/1_61_0/libs/spirit/doc/html/spirit/qi/referen… [2] <boost/spirit/home/qi/numeric/real_policies.hpp> [3]<boost/spirit/home/qi/numeric/detail/real_impl.hpp>

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RFC : About forking a C++11 standard library and adapt it to C++98 compilers
by Vicente J. Botet Escriba 07 Jun '16

07 Jun '16

Hi, Some of us have to work yet with C++98 compiler at work (due to well know reasons) and this for a long time. This is a reality. I was wondering about forking a public domain C++11/14/17 standard library and adapt it to C++98 compilers. This library could be seen as another TR1, an extension of the C++03 standard library. Does this make any sens? Would this project be of interest for the Boost/C++ community? I have not a clear idea of the cost of doing this work, how it should be done, what would be the limitations, ... but I'm sure that this would be quite useful on the projects that are forced to use C++98 and an excellent bridge to those that will move from C++98 to C++11 compilers. There are some Boost libraries that could be used to reduce the limitations, as Boost.Config/Predef, Boost.Move, ...and others that could be used as inspiration on how to implement them using C++98. Anyway, if you find that this will be useful to you at your work we will need your participation. Would you be interested in working on it? as a Boost community project? outside Boost, as an independent project? Comments and suggestion welcome. Best, Vicente P.S. The same can be done for C++14 standard libraries and the future standard C++17 libraries P.S.S. The same can be done for C++14 libraries and the future C++17 libraries but this time adapting to C++11 compilers (this will be much easier but the concerned community will be quite different ).

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Make libs/maintainers.txt a template file
by Daniel James 07 Jun '16

07 Jun '16

Hi, If you haven't noticed, on develop libs/libraries.htm is now a template which gets filled in as part of the documentation build. You can see the template and generated files at: https://github.com/boostorg/boost/blob/develop/libs/libraries.htm http://www.boost.org/doc/libs/develop/libs/libraries.htm This will be merged to master pretty soon. The only obstacle is updating the website automatically from the latest build, which should be happening very soon. The file libs/maintainers.txt is also automatically updated, but that's done in the repo itself, so that you have the full copy in you normal checkout. But I'm finding that people don't realise this, and we've had a few pull requests to update it manually. So instead, I think it might be a good idea to convert it to a template as well. This means you won't have a local copy, but will still be able to see a reasonably up to date copy online at: http://www.boost.org/doc/libs/develop/libs/maintainers.txt Any objections? I'm think of using similar templates for some other files, such as the root index.html (for the version number and new libraries). thanks, Daniel

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Cxx dual library
by Edward Diener 06 Jun '16

06 Jun '16

I have finished all the main work on the Cxx dual library at https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597. The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short. The library does this by defining object-like macros for including the appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge. The library came out of my initial PR to add such a feature to Boost.Config, and then I decided to create a separate library and expand on the functionality. The gist of the library is to write a single set of code for a particular implementation and have it work whether or not that code targets a Boost implementation or its C++ standard equivalent. The default algorithm will choose the C++ standard implementation if it is available, otherwise it chooses the Boost implementation. The default can be overriden for any of the 28 different implementations which CXXD supports. With all the talk about supporting C++11 or C++14 in new code, the library offers a way of supporting C++11 or C++14 standard libraries if available whether one writes in C++03 dialect or uses the new language features of C++11 on up. The Cxx dual library itself, being macro based, should work with any C++ code at that code's language level. The library itself is NOT, repeat NOT, an attempt to enforce a C++ language level for anybody who wants to use it. I have a little more work I am doing on increasing the support for Boost Build in the library, but all the central implementation of the library is complete in my mind. Questions, comments, or bug reports are always welcome, either here in this mailing list, in the Boost Library Incubator, or as Github issues, by those who are interested in trying the library out or reading the documentation. I will be using CXXD in another library on which I am working but hopefully others will find a use for it in their own code.

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[exception] Broken in master?
by John Maddock 06 Jun '16

06 Jun '16

Anything that includes Boost.Exception is currently broken on master for all compilers, for example: http://www.boost.org/development/tests/master/developer/output/teeks99-09j-… http://www.boost.org/development/tests/master/developer/output/Flast-FreeBS… The cause is the use of a partial-template specialization in info.hpp with no previous definition of class set_info_rv. Thanks, John.

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Boost.Fiber mini-review May 23 - June 1: review report
by Nat Goodspeed 05 Jun '16

05 Jun '16

The Boost.Fiber mini-review is now closed. Results: Bjorn Reese: YES Niall Douglas (private): YES Agustín K-ballo Bergé: YES Niall Douglas reminds me that in a previous mini-review he already voted to accept the Fiber library. Unless he stated that he had changed his mind, it would be reasonable to carry forward that "yes" vote. However, he did reaffirm his previous stance. In that spirit, let me remind the community of another couple previous positive votes: Eugene Yakubovich Antony Polukhin Significantly, there were no remaining NO votes. I therefore conclude that the Boost community ACCEPTS the Fiber library into the Boost family of libraries. On behalf of the Boost community, I would like to congratulate Oliver Kowalke not only for his engineering work, but for considerable patience in working to improve the library and its documentation. Thank you, Oliver!

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Re: [boost] Checking interest in std::get for PODs
by Bjorn Reese 04 Jun '16

04 Jun '16

On 06/03/2016 08:27 AM, Antony Polukhin wrote: > There's a C++14 library that is able to do basic reflections for PODs > without any macro magic or markup: https://github.com/apolukhin/magic_get Could the "Enums will be returned as their underlying type" limitation be partially worked around by allowing users to register their own enums?

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Checking interest in std::get for PODs
by Antony Polukhin 04 Jun '16

04 Jun '16

Hi, There's a C++14 library that is able to do basic reflections for PODs without any macro magic or markup: https://github.com/apolukhin/magic_get Would it be interesting for Boost? Could it pass Boost review if it has a reinterpret_cast in it? -- Best regards, Antony Polukhin

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Re: [boost] Cxx dual library
by Thomas Heller 04 Jun '16

04 Jun '16

Am 02.06.2016 8:56 nachm. schrieb "Edward Diener" <eldiener(a)tropicsoft.com>: > > I have finished all the main work on the Cxx dual library at https://github.com/eldiener/cxx_dual. The library is also in the Boost Library Incubator at > http://rrsd.com/blincubator.com/bi_library/cxx_dual-2/?gform_post_id=1597. > > The Cxx dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while using the same code to program either choice. An 'implementation' is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'dual library' in this documentation, or 'CXXD-mod' for short. > > The library does this by defining object-like macros for including the appropriate header file and namespace or using either the Boost library version or the C++ standard library version of a particular dual library. CXXD currently supports twenty eight different dual libraries, where the Boost version and the C++ standard version is nearly interchangeable in some respects. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge. Personally, I'm not a big fan of such a solution, especially when those macros "leak" into the public interface. We had a similar interface which would automatically switch between std and boost function. The result looked nice at first sight, however the subtle differences between the two led to various problems, one of which was that documenting the public interfaces containing this macro was very difficult, where does it point to know? Where should we send users to who look for more information about this function type? Should they be aware of both? Switching compilers or even boost version and now suddenly everything seems broken? The solution for us was to just decide which one to use and go with it, setting the requirements to the used standard library/boost version as needed.

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A retrospect on 'CMakeLists.txt' policy review
by David Sankel 04 Jun '16

04 Jun '16

Hello all, I wanted to thank everyone who participated in the CMakeLists.txt and related threads. I'm sorry I wasn't able to participate all the way through, but I found the majority of the posts to be civil and constructive (some of my own heated posts being notable exceptions). Here is my take away. No one is arguing that the current guidelines disallow authors from placing a CMakeLists.txt in the root of their library's directory. Some pointed out drawbacks of placing them there and recommended 'build/' or 'CMake/' instead. Others saw value in having CMakeLists.txt in the root directory, but felt these should be short wrappers where the real work is done in the 'build/' directory. Louis and Paul, I know you felt it important for your gitHub distribution to have 'CMakeLists.txt' in the root directory as is typical for CMake projects. Does this result satisfy your concerns? -- David Sankel

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[announcement] GitHub permission changes
by Daniel Pfeifer 03 Jun '16

03 Jun '16

Hi all, GitHub finally allows us to set permissions on the level of granularity that we always wanted. When we moved to GitHub, we received many request like "can I please get admin rights to my repository?" We wanted to do that, but it just was not possible. As a workaround, we have created a team per repository and many of those teams had just one member. That way, we could at least give you write access to individual repositories. Not quite what you requested, but at least something. Anyway, it is now possible to set permissions on a per repository level. I have started to delete the teams with a single member and added the member as the owner of the repository. How do those changes affect you? As the owner of a repository you have write access as before, but you can also add collaborators, modify the repository descriptions, enable/disable issue tracking and wiki, and so forth. I will continue this cleanup soon, but I need your input. For teams with multiple members, I don't know whether you want to share ownership or whether you prefer to have a single owner and additional contributors. Please create new issues for that matter: https://github.com/boostorg/admin/issues Cheers, Daniel

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Boost.Fiber mini-review May 23 - June 1
by Nat Goodspeed 02 Jun '16

02 Jun '16

Hi all, The Boost.Fiber candidate library by Oliver Kowalke begins a mini-review today, Monday May 23, which will close Wednesday June 1. It was last reviewed in September 2015; the verdict at that time was "not yet." Oliver has been working steadily to address review comments and to improve the library in other ways, and has brought the library back for mini-review. The updated documentation is here: http://olk.github.io/libs/fiber/doc/html/index.html The code is on the master branch of this repository: https://github.com/olk/boost-fiber/tree/master I believe it is Oliver's intention to respond to review feedback on the develop branch, leaving the master branch stable during the review. I will monitor reviews and discussion on both the boost-users@ list and the boost@ developers' list. Please include at least "fiber" and "review" in the subject line of your mail, e.g. by replying to this message. (Please reply to only ONE list, however.) I will also check the Boost Library Incubator for Fiber reviews: http://rrsd.com/blincubator.com/bi_library/fiber/?gform_post_id=859 though I check that less frequently than email. Please do remember to state in your review whether you think the library should be accepted as a Boost library. Thank you for your interest and your feedback! ----------------------------------------------------- Here follows a synopsis of issues raised during the September 2015 review: Cross-thread fiber migration: Evidently the community strongly desires the ability to transfer a suspended fiber from one thread to another. Now supported, with documentation. Cross-thread migration support implies a requirement to document the thread safety requirements of the customization API. Addressed. Standard required timing specifications: meet (30.2.4 Timing specifications [thread.req.timing]). Addressed. Adapt one or more existing test suites for thread facilities to validate the correctness of the Fiber library's synchronization constructs. The requester clarified in private mail that I misstated his suggestion: he wanted Oliver to review one or more such test suites to discover the kinds of issues that can arise with thread synchronization constructs. He has professed himself satisfied with the current state of the Fiber library's synchronization constructs. std::chrono support: ensure that wait_until() can accept any supported time_point specialization. Addressed. C++11 compatibility. Addressed. Document that this_fiber::yield() (et al.) are valid from main(), or in general from a thread function, as well as from explicitly-launched fibers. Addressed. Make shared_state lock requirements explicit: for example, make mark_ready_and_notify_() accept a std::unique_lock<>& (or &&) to force its caller to provide one. Addressed. Avoid holding mutex during condition_variable::notify_*() calls. Addressed. packaged_task must not decay-copy its task arguments. Addressed. Align fibers::async() signature, result description and invoke_helper implementation with std::async(). Avoid returning std::move(...). Addressed. Wait list implementation: try an intrusive linked list of fiber_context objects. Addressed. Avoid sleeping thread when no fibers are ready -- block on external event. Better handling of waiting tasks (decentralized wait queues?). Addressed. Optimization to resume awakened fiber on the thread that awakens it. Hooks provided. Template redundancy: eliminate duplication between specializations for T, T& and void. The future, shared_future, shared_state, promise and task_object templates were specifically cited. Addressed. Leverage predicate-based condition::wait() overload internally. Addressed. Nested schedulers: make schedulers be schedulable entities themselves. Not implemented. Improve robustness of `promise' handling in Asynchronous Callbacks documentation. Avoid overconfident remarks about it. Addressed. Fix Note overstating the requirements on condition_variable::wait(). Addressed.

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